Lookup NU author(s): Dr Olivier Joly,
Professor Alexander Thiele
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
Natural sounds can be characterised by their spectral content and temporal modulation, but how the brain is organized to analyse these two critical sound dimensions remains uncertain. Using functional magnetic resonance imaging, we demonstrate a topographical representation of amplitude modulation rate in the auditory cortex of awake macaques. The representation of this temporal dimension is organized in approximately concentric bands of equal rates across the superior temporal plane in both hemispheres, progressing from high rates in the posterior core to low rates in the anterior core and lateral belt cortex. In A1 the resulting gradient of modulation rate runs approximately perpendicular to the axis of the tonotopic gradient, suggesting an orthogonal organisation of spectral and temporal sound dimensions. In auditory belt areas this relationship is more complex. The data suggest a continuous representation of modulation rate across several physiological areas, in contradistinction to a separate representation of frequency within each area.
Author(s): Baumann S, Joly O, Rees A, Petkov CI, Sun L, Thiele A, Griffiths TD
Publication type: Article
Publication status: Published
Online publication date: 15/01/2015
Acceptance date: 14/01/2015
Date deposited: 17/12/2015
ISSN (electronic): 2050-084X
Publisher: eLife Science Publications Ltd.
PubMed id: 25590651
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